mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
b1c0857f62
rust/src/libsyntax/codemap.rs
Oliver Schneider 5a7fc9b33a Satisfy tidy
2018-05-21 18:43:11 +02:00

1294 lines
48 KiB
Rust
Raw Blame History

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! The CodeMap tracks all the source code used within a single crate, mapping
//! from integer byte positions to the original source code location. Each bit
//! of source parsed during crate parsing (typically files, in-memory strings,
//! or various bits of macro expansion) cover a continuous range of bytes in the
//! CodeMap and are represented by FileMaps. Byte positions are stored in
//! `spans` and used pervasively in the compiler. They are absolute positions
//! within the CodeMap, which upon request can be converted to line and column
//! information, source code snippets, etc.
pub use syntax_pos::*;
pub use syntax_pos::hygiene::{ExpnFormat, ExpnInfo, NameAndSpan};
pub use self::ExpnFormat::*;
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::stable_hasher::StableHasher;
use rustc_data_structures::sync::{Lrc, Lock, LockGuard};
use std::cmp;
use std::hash::Hash;
use std::path::{Path, PathBuf};
use std::env;
use std::fs;
use std::io::{self, Read};
use errors::CodeMapper;
/// Return the span itself if it doesn't come from a macro expansion,
/// otherwise return the call site span up to the `enclosing_sp` by
/// following the `expn_info` chain.
pub fn original_sp(sp: Span, enclosing_sp: Span) -> Span {
let call_site1 = sp.ctxt().outer().expn_info().map(|ei| ei.call_site);
let call_site2 = enclosing_sp.ctxt().outer().expn_info().map(|ei| ei.call_site);
match (call_site1, call_site2) {
(None, _) => sp,
(Some(call_site1), Some(call_site2)) if call_site1 == call_site2 => sp,
(Some(call_site1), _) => original_sp(call_site1, enclosing_sp),
}
}
#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
pub struct Spanned<T> {
pub node: T,
pub span: Span,
}
pub fn respan<T>(sp: Span, t: T) -> Spanned<T> {
Spanned {node: t, span: sp}
}
pub fn dummy_spanned<T>(t: T) -> Spanned<T> {
respan(DUMMY_SP, t)
}
// _____________________________________________________________________________
// FileMap, MultiByteChar, FileName, FileLines
//
/// An abstraction over the fs operations used by the Parser.
pub trait FileLoader {
/// Query the existence of a file.
fn file_exists(&self, path: &Path) -> bool;
/// Return an absolute path to a file, if possible.
fn abs_path(&self, path: &Path) -> Option<PathBuf>;
/// Read the contents of an UTF-8 file into memory.
fn read_file(&self, path: &Path) -> io::Result<String>;
}
/// A FileLoader that uses std::fs to load real files.
pub struct RealFileLoader;
impl FileLoader for RealFileLoader {
fn file_exists(&self, path: &Path) -> bool {
fs::metadata(path).is_ok()
}
fn abs_path(&self, path: &Path) -> Option<PathBuf> {
if path.is_absolute() {
Some(path.to_path_buf())
} else {
env::current_dir()
.ok()
.map(|cwd| cwd.join(path))
}
}
fn read_file(&self, path: &Path) -> io::Result<String> {
let mut src = String::new();
fs::File::open(path)?.read_to_string(&mut src)?;
Ok(src)
}
}
// This is a FileMap identifier that is used to correlate FileMaps between
// subsequent compilation sessions (which is something we need to do during
// incremental compilation).
#[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)]
pub struct StableFilemapId(u128);
impl StableFilemapId {
pub fn new(filemap: &FileMap) -> StableFilemapId {
let mut hasher = StableHasher::new();
filemap.name.hash(&mut hasher);
filemap.name_was_remapped.hash(&mut hasher);
filemap.unmapped_path.hash(&mut hasher);
StableFilemapId(hasher.finish())
}
}
// _____________________________________________________________________________
// CodeMap
//
pub(super) struct CodeMapFiles {
pub(super) file_maps: Vec<Lrc<FileMap>>,
stable_id_to_filemap: FxHashMap<StableFilemapId, Lrc<FileMap>>
}
pub struct CodeMap {
pub(super) files: Lock<CodeMapFiles>,
file_loader: Box<FileLoader + Sync + Send>,
// This is used to apply the file path remapping as specified via
// --remap-path-prefix to all FileMaps allocated within this CodeMap.
path_mapping: FilePathMapping,
/// In case we are in a doctest, replace all file names with the PathBuf,
/// and add the given offsets to the line info
doctest_offset: Option<(FileName, isize)>,
}
impl CodeMap {
pub fn new(path_mapping: FilePathMapping) -> CodeMap {
CodeMap {
files: Lock::new(CodeMapFiles {
file_maps: Vec::new(),
stable_id_to_filemap: FxHashMap(),
}),
file_loader: Box::new(RealFileLoader),
path_mapping,
doctest_offset: None,
}
}
pub fn new_doctest(path_mapping: FilePathMapping,
file: FileName, line: isize) -> CodeMap {
CodeMap {
doctest_offset: Some((file, line)),
..CodeMap::new(path_mapping)
}
}
pub fn with_file_loader(file_loader: Box<FileLoader + Sync + Send>,
path_mapping: FilePathMapping)
-> CodeMap {
CodeMap {
files: Lock::new(CodeMapFiles {
file_maps: Vec::new(),
stable_id_to_filemap: FxHashMap(),
}),
file_loader: file_loader,
path_mapping,
doctest_offset: None,
}
}
pub fn path_mapping(&self) -> &FilePathMapping {
&self.path_mapping
}
pub fn file_exists(&self, path: &Path) -> bool {
self.file_loader.file_exists(path)
}
pub fn load_file(&self, path: &Path) -> io::Result<Lrc<FileMap>> {
let src = self.file_loader.read_file(path)?;
let filename = if let Some((ref name, _)) = self.doctest_offset {
name.clone()
} else {
path.to_owned().into()
};
Ok(self.new_filemap(filename, src))
}
pub fn files(&self) -> LockGuard<Vec<Lrc<FileMap>>> {
LockGuard::map(self.files.borrow(), |files| &mut files.file_maps)
}
pub fn filemap_by_stable_id(&self, stable_id: StableFilemapId) -> Option<Lrc<FileMap>> {
self.files.borrow().stable_id_to_filemap.get(&stable_id).map(|fm| fm.clone())
}
fn next_start_pos(&self) -> usize {
match self.files.borrow().file_maps.last() {
None => 0,
// Add one so there is some space between files. This lets us distinguish
// positions in the codemap, even in the presence of zero-length files.
Some(last) => last.end_pos.to_usize() + 1,
}
}
/// Creates a new filemap without setting its line information. If you don't
/// intend to set the line information yourself, you should use new_filemap_and_lines.
/// This does not ensure that only one FileMap exists per file name.
pub fn new_filemap(&self, filename: FileName, src: String) -> Lrc<FileMap> {
let start_pos = self.next_start_pos();
// The path is used to determine the directory for loading submodules and
// include files, so it must be before remapping.
// Note that filename may not be a valid path, eg it may be `<anon>` etc,
// but this is okay because the directory determined by `path.pop()` will
// be empty, so the working directory will be used.
let unmapped_path = filename.clone();
let (filename, was_remapped) = match filename {
FileName::Real(filename) => {
let (filename, was_remapped) = self.path_mapping.map_prefix(filename);
(FileName::Real(filename), was_remapped)
},
other => (other, false),
};
let filemap = Lrc::new(FileMap::new(
filename,
was_remapped,
unmapped_path,
src,
Pos::from_usize(start_pos),
));
let mut files = self.files.borrow_mut();
files.file_maps.push(filemap.clone());
files.stable_id_to_filemap.insert(StableFilemapId::new(&filemap), filemap.clone());
filemap
}
/// Creates a new filemap and sets its line information.
/// This does not ensure that only one FileMap exists per file name.
pub fn new_filemap_and_lines(&self, filename: &Path, src: &str) -> Lrc<FileMap> {
let fm = self.new_filemap(filename.to_owned().into(), src.to_owned());
let mut byte_pos: u32 = fm.start_pos.0;
for line in src.lines() {
// register the start of this line
fm.next_line(BytePos(byte_pos));
// update byte_pos to include this line and the \n at the end
byte_pos += line.len() as u32 + 1;
}
fm
}
/// Allocates a new FileMap representing a source file from an external
/// crate. The source code of such an "imported filemap" is not available,
/// but we still know enough to generate accurate debuginfo location
/// information for things inlined from other crates.
pub fn new_imported_filemap(&self,
filename: FileName,
name_was_remapped: bool,
crate_of_origin: u32,
src_hash: u128,
name_hash: u128,
source_len: usize,
mut file_local_lines: Vec<BytePos>,
mut file_local_multibyte_chars: Vec<MultiByteChar>,
mut file_local_non_narrow_chars: Vec<NonNarrowChar>)
-> Lrc<FileMap> {
let start_pos = self.next_start_pos();
let end_pos = Pos::from_usize(start_pos + source_len);
let start_pos = Pos::from_usize(start_pos);
for pos in &mut file_local_lines {
*pos = *pos + start_pos;
}
for mbc in &mut file_local_multibyte_chars {
mbc.pos = mbc.pos + start_pos;
}
for swc in &mut file_local_non_narrow_chars {
*swc = *swc + start_pos;
}
let filemap = Lrc::new(FileMap {
name: filename,
name_was_remapped,
unmapped_path: None,
crate_of_origin,
src: None,
src_hash,
external_src: Lock::new(ExternalSource::AbsentOk),
start_pos,
end_pos,
lines: Lock::new(file_local_lines),
multibyte_chars: Lock::new(file_local_multibyte_chars),
non_narrow_chars: Lock::new(file_local_non_narrow_chars),
name_hash,
});
let mut files = self.files.borrow_mut();
files.file_maps.push(filemap.clone());
files.stable_id_to_filemap.insert(StableFilemapId::new(&filemap), filemap.clone());
filemap
}
pub fn mk_substr_filename(&self, sp: Span) -> String {
let pos = self.lookup_char_pos(sp.lo());
format!("<{}:{}:{}>",
pos.file.name,
pos.line,
pos.col.to_usize() + 1)
}
// If there is a doctest_offset, apply it to the line
pub fn doctest_offset_line(&self, mut orig: usize) -> usize {
if let Some((_, line)) = self.doctest_offset {
if line >= 0 {
orig = orig + line as usize;
} else {
orig = orig - (-line) as usize;
}
}
orig
}
/// Lookup source information about a BytePos
pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
let chpos = self.bytepos_to_file_charpos(pos);
match self.lookup_line(pos) {
Ok(FileMapAndLine { fm: f, line: a }) => {
let line = a + 1; // Line numbers start at 1
let linebpos = (*f.lines.borrow())[a];
let linechpos = self.bytepos_to_file_charpos(linebpos);
let col = chpos - linechpos;
let col_display = {
let non_narrow_chars = f.non_narrow_chars.borrow();
let start_width_idx = non_narrow_chars
.binary_search_by_key(&linebpos, |x| x.pos())
.unwrap_or_else(|x| x);
let end_width_idx = non_narrow_chars
.binary_search_by_key(&pos, |x| x.pos())
.unwrap_or_else(|x| x);
let special_chars = end_width_idx - start_width_idx;
let non_narrow: usize =
non_narrow_chars[start_width_idx..end_width_idx]
.into_iter()
.map(|x| x.width())
.sum();
col.0 - special_chars + non_narrow
};
debug!("byte pos {:?} is on the line at byte pos {:?}",
pos, linebpos);
debug!("char pos {:?} is on the line at char pos {:?}",
chpos, linechpos);
debug!("byte is on line: {}", line);
assert!(chpos >= linechpos);
Loc {
file: f,
line,
col,
col_display,
}
}
Err(f) => {
let col_display = {
let non_narrow_chars = f.non_narrow_chars.borrow();
let end_width_idx = non_narrow_chars
.binary_search_by_key(&pos, |x| x.pos())
.unwrap_or_else(|x| x);
let non_narrow: usize =
non_narrow_chars[0..end_width_idx]
.into_iter()
.map(|x| x.width())
.sum();
chpos.0 - end_width_idx + non_narrow
};
Loc {
file: f,
line: 0,
col: chpos,
col_display,
}
}
}
}
// If the relevant filemap is empty, we don't return a line number.
pub fn lookup_line(&self, pos: BytePos) -> Result<FileMapAndLine, Lrc<FileMap>> {
let idx = self.lookup_filemap_idx(pos);
let f = (*self.files.borrow().file_maps)[idx].clone();
match f.lookup_line(pos) {
Some(line) => Ok(FileMapAndLine { fm: f, line: line }),
None => Err(f)
}
}
pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt {
let loc = self.lookup_char_pos(pos);
LocWithOpt {
filename: loc.file.name.clone(),
line: loc.line,
col: loc.col,
file: Some(loc.file)
}
}
/// Returns `Some(span)`, a union of the lhs and rhs span. The lhs must precede the rhs. If
/// there are gaps between lhs and rhs, the resulting union will cross these gaps.
/// For this to work, the spans have to be:
///
/// * the ctxt of both spans much match
/// * the lhs span needs to end on the same line the rhs span begins
/// * the lhs span must start at or before the rhs span
pub fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
// make sure we're at the same expansion id
if sp_lhs.ctxt() != sp_rhs.ctxt() {
return None;
}
let lhs_end = match self.lookup_line(sp_lhs.hi()) {
Ok(x) => x,
Err(_) => return None
};
let rhs_begin = match self.lookup_line(sp_rhs.lo()) {
Ok(x) => x,
Err(_) => return None
};
// if we must cross lines to merge, don't merge
if lhs_end.line != rhs_begin.line {
return None;
}
// ensure these follow the expected order and we don't overlap
if (sp_lhs.lo() <= sp_rhs.lo()) && (sp_lhs.hi() <= sp_rhs.lo()) {
Some(sp_lhs.to(sp_rhs))
} else {
None
}
}
pub fn span_to_string(&self, sp: Span) -> String {
if self.files.borrow().file_maps.is_empty() && sp.source_equal(&DUMMY_SP) {
return "no-location".to_string();
}
let lo = self.lookup_char_pos_adj(sp.lo());
let hi = self.lookup_char_pos_adj(sp.hi());
format!("{}:{}:{}: {}:{}",
lo.filename,
lo.line,
lo.col.to_usize() + 1,
hi.line,
hi.col.to_usize() + 1)
}
pub fn span_to_filename(&self, sp: Span) -> FileName {
self.lookup_char_pos(sp.lo()).file.name.clone()
}
pub fn span_to_unmapped_path(&self, sp: Span) -> FileName {
self.lookup_char_pos(sp.lo()).file.unmapped_path.clone()
.expect("CodeMap::span_to_unmapped_path called for imported FileMap?")
}
pub fn is_multiline(&self, sp: Span) -> bool {
let lo = self.lookup_char_pos(sp.lo());
let hi = self.lookup_char_pos(sp.hi());
lo.line != hi.line
}
pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
debug!("span_to_lines(sp={:?})", sp);
if sp.lo() > sp.hi() {
return Err(SpanLinesError::IllFormedSpan(sp));
}
let lo = self.lookup_char_pos(sp.lo());
debug!("span_to_lines: lo={:?}", lo);
let hi = self.lookup_char_pos(sp.hi());
debug!("span_to_lines: hi={:?}", hi);
if lo.file.start_pos != hi.file.start_pos {
return Err(SpanLinesError::DistinctSources(DistinctSources {
begin: (lo.file.name.clone(), lo.file.start_pos),
end: (hi.file.name.clone(), hi.file.start_pos),
}));
}
assert!(hi.line >= lo.line);
let mut lines = Vec::with_capacity(hi.line - lo.line + 1);
// The span starts partway through the first line,
// but after that it starts from offset 0.
let mut start_col = lo.col;
// For every line but the last, it extends from `start_col`
// and to the end of the line. Be careful because the line
// numbers in Loc are 1-based, so we subtract 1 to get 0-based
// lines.
for line_index in lo.line-1 .. hi.line-1 {
let line_len = lo.file.get_line(line_index)
.map(|s| s.chars().count())
.unwrap_or(0);
lines.push(LineInfo { line_index,
start_col,
end_col: CharPos::from_usize(line_len) });
start_col = CharPos::from_usize(0);
}
// For the last line, it extends from `start_col` to `hi.col`:
lines.push(LineInfo { line_index: hi.line - 1,
start_col,
end_col: hi.col });
Ok(FileLines {file: lo.file, lines: lines})
}
/// Extract the source surrounding the given `Span` using the `extract_source` function. The
/// extract function takes three arguments: a string slice containing the source, an index in
/// the slice for the beginning of the span and an index in the slice for the end of the span.
fn span_to_source<F>(&self, sp: Span, extract_source: F) -> Result<String, SpanSnippetError>
where F: Fn(&str, usize, usize) -> String
{
if sp.lo() > sp.hi() {
return Err(SpanSnippetError::IllFormedSpan(sp));
}
let local_begin = self.lookup_byte_offset(sp.lo());
let local_end = self.lookup_byte_offset(sp.hi());
if local_begin.fm.start_pos != local_end.fm.start_pos {
return Err(SpanSnippetError::DistinctSources(DistinctSources {
begin: (local_begin.fm.name.clone(),
local_begin.fm.start_pos),
end: (local_end.fm.name.clone(),
local_end.fm.start_pos)
}));
} else {
self.ensure_filemap_source_present(local_begin.fm.clone());
let start_index = local_begin.pos.to_usize();
let end_index = local_end.pos.to_usize();
let source_len = (local_begin.fm.end_pos -
local_begin.fm.start_pos).to_usize();
if start_index > end_index || end_index > source_len {
return Err(SpanSnippetError::MalformedForCodemap(
MalformedCodemapPositions {
name: local_begin.fm.name.clone(),
source_len,
begin_pos: local_begin.pos,
end_pos: local_end.pos,
}));
}
if let Some(ref src) = local_begin.fm.src {
return Ok(extract_source(src, start_index, end_index));
} else if let Some(src) = local_begin.fm.external_src.borrow().get_source() {
return Ok(extract_source(src, start_index, end_index));
} else {
return Err(SpanSnippetError::SourceNotAvailable {
filename: local_begin.fm.name.clone()
});
}
}
}
/// Return the source snippet as `String` corresponding to the given `Span`
pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> {
self.span_to_source(sp, |src, start_index, end_index| src[start_index..end_index]
.to_string())
}
/// Return the source snippet as `String` before the given `Span`
pub fn span_to_prev_source(&self, sp: Span) -> Result<String, SpanSnippetError> {
self.span_to_source(sp, |src, start_index, _| src[..start_index].to_string())
}
/// Extend the given `Span` to just after the previous occurrence of `c`. Return the same span
/// if no character could be found or if an error occurred while retrieving the code snippet.
pub fn span_extend_to_prev_char(&self, sp: Span, c: char) -> Span {
if let Ok(prev_source) = self.span_to_prev_source(sp) {
let prev_source = prev_source.rsplit(c).nth(0).unwrap_or("").trim_left();
if !prev_source.is_empty() && !prev_source.contains('\n') {
return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
}
}
sp
}
/// Extend the given `Span` to just after the previous occurrence of `pat` when surrounded by
/// whitespace. Return the same span if no character could be found or if an error occurred
/// while retrieving the code snippet.
pub fn span_extend_to_prev_str(&self, sp: Span, pat: &str, accept_newlines: bool) -> Span {
// assure that the pattern is delimited, to avoid the following
// fn my_fn()
// ^^^^ returned span without the check
// ---------- correct span
for ws in &[" ", "\t", "\n"] {
let pat = pat.to_owned() + ws;
if let Ok(prev_source) = self.span_to_prev_source(sp) {
let prev_source = prev_source.rsplit(&pat).nth(0).unwrap_or("").trim_left();
if !prev_source.is_empty() && (!prev_source.contains('\n') || accept_newlines) {
return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
}
}
}
sp
}
/// Given a `Span`, try to get a shorter span ending before the first occurrence of `c` `char`
pub fn span_until_char(&self, sp: Span, c: char) -> Span {
match self.span_to_snippet(sp) {
Ok(snippet) => {
let snippet = snippet.split(c).nth(0).unwrap_or("").trim_right();
if !snippet.is_empty() && !snippet.contains('\n') {
sp.with_hi(BytePos(sp.lo().0 + snippet.len() as u32))
} else {
sp
}
}
_ => sp,
}
}
/// Given a `Span`, try to get a shorter span ending just after the first occurrence of `char`
/// `c`.
pub fn span_through_char(&self, sp: Span, c: char) -> Span {
if let Ok(snippet) = self.span_to_snippet(sp) {
if let Some(offset) = snippet.find(c) {
return sp.with_hi(BytePos(sp.lo().0 + (offset + c.len_utf8()) as u32));
}
}
sp
}
/// Given a `Span`, get a new `Span` covering the first token and all its trailing whitespace or
/// the original `Span`.
///
/// If `sp` points to `"let mut x"`, then a span pointing at `"let "` will be returned.
pub fn span_until_non_whitespace(&self, sp: Span) -> Span {
let mut whitespace_found = false;
self.span_take_while(sp, |c| {
if !whitespace_found && c.is_whitespace() {
whitespace_found = true;
}
if whitespace_found && !c.is_whitespace() {
false
} else {
true
}
})
}
/// Given a `Span`, get a new `Span` covering the first token without its trailing whitespace or
/// the original `Span` in case of error.
///
/// If `sp` points to `"let mut x"`, then a span pointing at `"let"` will be returned.
pub fn span_until_whitespace(&self, sp: Span) -> Span {
self.span_take_while(sp, |c| !c.is_whitespace())
}
/// Given a `Span`, get a shorter one until `predicate` yields false.
pub fn span_take_while<P>(&self, sp: Span, predicate: P) -> Span
where P: for <'r> FnMut(&'r char) -> bool
{
if let Ok(snippet) = self.span_to_snippet(sp) {
let offset = snippet.chars()
.take_while(predicate)
.map(|c| c.len_utf8())
.sum::<usize>();
sp.with_hi(BytePos(sp.lo().0 + (offset as u32)))
} else {
sp
}
}
pub fn def_span(&self, sp: Span) -> Span {
self.span_until_char(sp, '{')
}
/// Returns a new span representing just the end-point of this span
pub fn end_point(&self, sp: Span) -> Span {
let pos = sp.hi().0;
let width = self.find_width_of_character_at_span(sp, false);
let corrected_end_position = pos.checked_sub(width).unwrap_or(pos);
let end_point = BytePos(cmp::max(corrected_end_position, sp.lo().0));
sp.with_lo(end_point)
}
/// Returns a new span representing the next character after the end-point of this span
pub fn next_point(&self, sp: Span) -> Span {
let start_of_next_point = sp.hi().0;
let width = self.find_width_of_character_at_span(sp, true);
// If the width is 1, then the next span should point to the same `lo` and `hi`. However,
// in the case of a multibyte character, where the width != 1, the next span should
// span multiple bytes to include the whole character.
let end_of_next_point = start_of_next_point.checked_add(
width - 1).unwrap_or(start_of_next_point);
let end_of_next_point = BytePos(cmp::max(sp.lo().0 + 1, end_of_next_point));
Span::new(BytePos(start_of_next_point), end_of_next_point, sp.ctxt())
}
/// Finds the width of a character, either before or after the provided span.
fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 {
// Disregard malformed spans and assume a one-byte wide character.
if sp.lo() >= sp.hi() {
debug!("find_width_of_character_at_span: early return malformed span");
return 1;
}
let local_begin = self.lookup_byte_offset(sp.lo());
let local_end = self.lookup_byte_offset(sp.hi());
debug!("find_width_of_character_at_span: local_begin=`{:?}`, local_end=`{:?}`",
local_begin, local_end);
let start_index = local_begin.pos.to_usize();
let end_index = local_end.pos.to_usize();
debug!("find_width_of_character_at_span: start_index=`{:?}`, end_index=`{:?}`",
start_index, end_index);
// Disregard indexes that are at the start or end of their spans, they can't fit bigger
// characters.
if (!forwards && end_index == usize::min_value()) ||
(forwards && start_index == usize::max_value()) {
debug!("find_width_of_character_at_span: start or end of span, cannot be multibyte");
return 1;
}
let source_len = (local_begin.fm.end_pos - local_begin.fm.start_pos).to_usize();
debug!("find_width_of_character_at_span: source_len=`{:?}`", source_len);
// Ensure indexes are also not malformed.
if start_index > end_index || end_index > source_len {
debug!("find_width_of_character_at_span: source indexes are malformed");
return 1;
}
let src = local_begin.fm.external_src.borrow();
// We need to extend the snippet to the end of the src rather than to end_index so when
// searching forwards for boundaries we've got somewhere to search.
let snippet = if let Some(ref src) = local_begin.fm.src {
let len = src.len();
(&src[start_index..len])
} else if let Some(src) = src.get_source() {
let len = src.len();
(&src[start_index..len])
} else {
return 1;
};
debug!("find_width_of_character_at_span: snippet=`{:?}`", snippet);
let mut target = if forwards { end_index + 1 } else { end_index - 1 };
debug!("find_width_of_character_at_span: initial target=`{:?}`", target);
while !snippet.is_char_boundary(target - start_index) && target < source_len {
target = if forwards {
target + 1
} else {
match target.checked_sub(1) {
Some(target) => target,
None => {
break;
}
}
};
debug!("find_width_of_character_at_span: target=`{:?}`", target);
}
debug!("find_width_of_character_at_span: final target=`{:?}`", target);
if forwards {
(target - end_index) as u32
} else {
(end_index - target) as u32
}
}
pub fn get_filemap(&self, filename: &FileName) -> Option<Lrc<FileMap>> {
for fm in self.files.borrow().file_maps.iter() {
if *filename == fm.name {
return Some(fm.clone());
}
}
None
}
/// For a global BytePos compute the local offset within the containing FileMap
pub fn lookup_byte_offset(&self, bpos: BytePos) -> FileMapAndBytePos {
let idx = self.lookup_filemap_idx(bpos);
let fm = (*self.files.borrow().file_maps)[idx].clone();
let offset = bpos - fm.start_pos;
FileMapAndBytePos {fm: fm, pos: offset}
}
/// Converts an absolute BytePos to a CharPos relative to the filemap.
pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos {
let idx = self.lookup_filemap_idx(bpos);
let map = &(*self.files.borrow().file_maps)[idx];
// The number of extra bytes due to multibyte chars in the FileMap
let mut total_extra_bytes = 0;
for mbc in map.multibyte_chars.borrow().iter() {
debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos);
if mbc.pos < bpos {
// every character is at least one byte, so we only
// count the actual extra bytes.
total_extra_bytes += mbc.bytes - 1;
// We should never see a byte position in the middle of a
// character
assert!(bpos.to_usize() >= mbc.pos.to_usize() + mbc.bytes);
} else {
break;
}
}
assert!(map.start_pos.to_usize() + total_extra_bytes <= bpos.to_usize());
CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes)
}
// Return the index of the filemap (in self.files) which contains pos.
pub fn lookup_filemap_idx(&self, pos: BytePos) -> usize {
let files = self.files.borrow();
let files = &files.file_maps;
let count = files.len();
// Binary search for the filemap.
let mut a = 0;
let mut b = count;
while b - a > 1 {
let m = (a + b) / 2;
if files[m].start_pos > pos {
b = m;
} else {
a = m;
}
}
assert!(a < count, "position {} does not resolve to a source location", pos.to_usize());
return a;
}
pub fn count_lines(&self) -> usize {
self.files().iter().fold(0, |a, f| a + f.count_lines())
}
pub fn generate_fn_name_span(&self, span: Span) -> Option<Span> {
let prev_span = self.span_extend_to_prev_str(span, "fn", true);
self.span_to_snippet(prev_span).map(|snippet| {
let len = snippet.find(|c: char| !c.is_alphanumeric() && c != '_')
.expect("no label after fn");
prev_span.with_hi(BytePos(prev_span.lo().0 + len as u32))
}).ok()
}
/// Take the span of a type parameter in a function signature and try to generate a span for the
/// function name (with generics) and a new snippet for this span with the pointed type
/// parameter as a new local type parameter.
///
/// For instance:
/// ```rust,ignore (pseudo-Rust)
/// // Given span
/// fn my_function(param: T)
/// // ^ Original span
///
/// // Result
/// fn my_function(param: T)
/// // ^^^^^^^^^^^ Generated span with snippet `my_function<T>`
/// ```
///
/// Attention: The method used is very fragile since it essentially duplicates the work of the
/// parser. If you need to use this function or something similar, please consider updating the
/// codemap functions and this function to something more robust.
pub fn generate_local_type_param_snippet(&self, span: Span) -> Option<(Span, String)> {
// Try to extend the span to the previous "fn" keyword to retrieve the function
// signature
let sugg_span = self.span_extend_to_prev_str(span, "fn", false);
if sugg_span != span {
if let Ok(snippet) = self.span_to_snippet(sugg_span) {
// Consume the function name
let mut offset = snippet.find(|c: char| !c.is_alphanumeric() && c != '_')
.expect("no label after fn");
// Consume the generics part of the function signature
let mut bracket_counter = 0;
let mut last_char = None;
for c in snippet[offset..].chars() {
match c {
'<' => bracket_counter += 1,
'>' => bracket_counter -= 1,
'(' => if bracket_counter == 0 { break; }
_ => {}
}
offset += c.len_utf8();
last_char = Some(c);
}
// Adjust the suggestion span to encompass the function name with its generics
let sugg_span = sugg_span.with_hi(BytePos(sugg_span.lo().0 + offset as u32));
// Prepare the new suggested snippet to append the type parameter that triggered
// the error in the generics of the function signature
let mut new_snippet = if last_char == Some('>') {
format!("{}, ", &snippet[..(offset - '>'.len_utf8())])
} else {
format!("{}<", &snippet[..offset])
};
new_snippet.push_str(&self.span_to_snippet(span).unwrap_or("T".to_string()));
new_snippet.push('>');
return Some((sugg_span, new_snippet));
}
}
None
}
}
impl CodeMapper for CodeMap {
fn lookup_char_pos(&self, pos: BytePos) -> Loc {
self.lookup_char_pos(pos)
}
fn span_to_lines(&self, sp: Span) -> FileLinesResult {
self.span_to_lines(sp)
}
fn span_to_string(&self, sp: Span) -> String {
self.span_to_string(sp)
}
fn span_to_filename(&self, sp: Span) -> FileName {
self.span_to_filename(sp)
}
fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
self.merge_spans(sp_lhs, sp_rhs)
}
fn call_span_if_macro(&self, sp: Span) -> Span {
if self.span_to_filename(sp.clone()).is_macros() {
let v = sp.macro_backtrace();
if let Some(use_site) = v.last() {
return use_site.call_site;
}
}
sp
}
fn ensure_filemap_source_present(&self, file_map: Lrc<FileMap>) -> bool {
file_map.add_external_src(
|| match file_map.name {
FileName::Real(ref name) => self.file_loader.read_file(name).ok(),
_ => None,
}
)
}
fn doctest_offset_line(&self, line: usize) -> usize {
self.doctest_offset_line(line)
}
}
#[derive(Clone)]
pub struct FilePathMapping {
mapping: Vec<(PathBuf, PathBuf)>,
}
impl FilePathMapping {
pub fn empty() -> FilePathMapping {
FilePathMapping {
mapping: vec![]
}
}
pub fn new(mapping: Vec<(PathBuf, PathBuf)>) -> FilePathMapping {
FilePathMapping {
mapping,
}
}
/// Applies any path prefix substitution as defined by the mapping.
/// The return value is the remapped path and a boolean indicating whether
/// the path was affected by the mapping.
pub fn map_prefix(&self, path: PathBuf) -> (PathBuf, bool) {
// NOTE: We are iterating over the mapping entries from last to first
// because entries specified later on the command line should
// take precedence.
for &(ref from, ref to) in self.mapping.iter().rev() {
if let Ok(rest) = path.strip_prefix(from) {
return (to.join(rest), true);
}
}
(path, false)
}
}
// _____________________________________________________________________________
// Tests
//
#[cfg(test)]
mod tests {
use super::*;
use std::borrow::Cow;
use rustc_data_structures::sync::Lrc;
#[test]
fn t1 () {
let cm = CodeMap::new(FilePathMapping::empty());
let fm = cm.new_filemap(PathBuf::from("blork.rs").into(),
"first line.\nsecond line".to_string());
fm.next_line(BytePos(0));
// Test we can get lines with partial line info.
assert_eq!(fm.get_line(0), Some(Cow::from("first line.")));
// TESTING BROKEN BEHAVIOR: line break declared before actual line break.
fm.next_line(BytePos(10));
assert_eq!(fm.get_line(1), Some(Cow::from(".")));
fm.next_line(BytePos(12));
assert_eq!(fm.get_line(2), Some(Cow::from("second line")));
}
#[test]
#[should_panic]
fn t2 () {
let cm = CodeMap::new(FilePathMapping::empty());
let fm = cm.new_filemap(PathBuf::from("blork.rs").into(),
"first line.\nsecond line".to_string());
// TESTING *REALLY* BROKEN BEHAVIOR:
fm.next_line(BytePos(0));
fm.next_line(BytePos(10));
fm.next_line(BytePos(2));
}
fn init_code_map() -> CodeMap {
let cm = CodeMap::new(FilePathMapping::empty());
let fm1 = cm.new_filemap(PathBuf::from("blork.rs").into(),
"first line.\nsecond line".to_string());
let fm2 = cm.new_filemap(PathBuf::from("empty.rs").into(),
"".to_string());
let fm3 = cm.new_filemap(PathBuf::from("blork2.rs").into(),
"first line.\nsecond line".to_string());
fm1.next_line(BytePos(0));
fm1.next_line(BytePos(12));
fm2.next_line(fm2.start_pos);
fm3.next_line(fm3.start_pos);
fm3.next_line(fm3.start_pos + BytePos(12));
cm
}
#[test]
fn t3() {
// Test lookup_byte_offset
let cm = init_code_map();
let fmabp1 = cm.lookup_byte_offset(BytePos(23));
assert_eq!(fmabp1.fm.name, PathBuf::from("blork.rs").into());
assert_eq!(fmabp1.pos, BytePos(23));
let fmabp1 = cm.lookup_byte_offset(BytePos(24));
assert_eq!(fmabp1.fm.name, PathBuf::from("empty.rs").into());
assert_eq!(fmabp1.pos, BytePos(0));
let fmabp2 = cm.lookup_byte_offset(BytePos(25));
assert_eq!(fmabp2.fm.name, PathBuf::from("blork2.rs").into());
assert_eq!(fmabp2.pos, BytePos(0));
}
#[test]
fn t4() {
// Test bytepos_to_file_charpos
let cm = init_code_map();
let cp1 = cm.bytepos_to_file_charpos(BytePos(22));
assert_eq!(cp1, CharPos(22));
let cp2 = cm.bytepos_to_file_charpos(BytePos(25));
assert_eq!(cp2, CharPos(0));
}
#[test]
fn t5() {
// Test zero-length filemaps.
let cm = init_code_map();
let loc1 = cm.lookup_char_pos(BytePos(22));
assert_eq!(loc1.file.name, PathBuf::from("blork.rs").into());
assert_eq!(loc1.line, 2);
assert_eq!(loc1.col, CharPos(10));
let loc2 = cm.lookup_char_pos(BytePos(25));
assert_eq!(loc2.file.name, PathBuf::from("blork2.rs").into());
assert_eq!(loc2.line, 1);
assert_eq!(loc2.col, CharPos(0));
}
fn init_code_map_mbc() -> CodeMap {
let cm = CodeMap::new(FilePathMapping::empty());
// € is a three byte utf8 char.
let fm1 =
cm.new_filemap(PathBuf::from("blork.rs").into(),
"fir€st €€€€ line.\nsecond line".to_string());
let fm2 = cm.new_filemap(PathBuf::from("blork2.rs").into(),
"first line€€.\n€ second line".to_string());
fm1.next_line(BytePos(0));
fm1.next_line(BytePos(28));
fm2.next_line(fm2.start_pos);
fm2.next_line(fm2.start_pos + BytePos(20));
fm1.record_multibyte_char(BytePos(3), 3);
fm1.record_multibyte_char(BytePos(9), 3);
fm1.record_multibyte_char(BytePos(12), 3);
fm1.record_multibyte_char(BytePos(15), 3);
fm1.record_multibyte_char(BytePos(18), 3);
fm2.record_multibyte_char(fm2.start_pos + BytePos(10), 3);
fm2.record_multibyte_char(fm2.start_pos + BytePos(13), 3);
fm2.record_multibyte_char(fm2.start_pos + BytePos(18), 3);
cm
}
#[test]
fn t6() {
// Test bytepos_to_file_charpos in the presence of multi-byte chars
let cm = init_code_map_mbc();
let cp1 = cm.bytepos_to_file_charpos(BytePos(3));
assert_eq!(cp1, CharPos(3));
let cp2 = cm.bytepos_to_file_charpos(BytePos(6));
assert_eq!(cp2, CharPos(4));
let cp3 = cm.bytepos_to_file_charpos(BytePos(56));
assert_eq!(cp3, CharPos(12));
let cp4 = cm.bytepos_to_file_charpos(BytePos(61));
assert_eq!(cp4, CharPos(15));
}
#[test]
fn t7() {
// Test span_to_lines for a span ending at the end of filemap
let cm = init_code_map();
let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
let file_lines = cm.span_to_lines(span).unwrap();
assert_eq!(file_lines.file.name, PathBuf::from("blork.rs").into());
assert_eq!(file_lines.lines.len(), 1);
assert_eq!(file_lines.lines[0].line_index, 1);
}
/// Given a string like " ~~~~~~~~~~~~ ", produces a span
/// converting that range. The idea is that the string has the same
/// length as the input, and we uncover the byte positions. Note
/// that this can span lines and so on.
fn span_from_selection(input: &str, selection: &str) -> Span {
assert_eq!(input.len(), selection.len());
let left_index = selection.find('~').unwrap() as u32;
let right_index = selection.rfind('~').map(|x|x as u32).unwrap_or(left_index);
Span::new(BytePos(left_index), BytePos(right_index + 1), NO_EXPANSION)
}
/// Test span_to_snippet and span_to_lines for a span converting 3
/// lines in the middle of a file.
#[test]
fn span_to_snippet_and_lines_spanning_multiple_lines() {
let cm = CodeMap::new(FilePathMapping::empty());
let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
let selection = " \n ~~\n~~~\n~~~~~ \n \n";
cm.new_filemap_and_lines(Path::new("blork.rs"), inputtext);
let span = span_from_selection(inputtext, selection);
// check that we are extracting the text we thought we were extracting
assert_eq!(&cm.span_to_snippet(span).unwrap(), "BB\nCCC\nDDDDD");
// check that span_to_lines gives us the complete result with the lines/cols we expected
let lines = cm.span_to_lines(span).unwrap();
let expected = vec![
LineInfo { line_index: 1, start_col: CharPos(4), end_col: CharPos(6) },
LineInfo { line_index: 2, start_col: CharPos(0), end_col: CharPos(3) },
LineInfo { line_index: 3, start_col: CharPos(0), end_col: CharPos(5) }
];
assert_eq!(lines.lines, expected);
}
#[test]
fn t8() {
// Test span_to_snippet for a span ending at the end of filemap
let cm = init_code_map();
let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
let snippet = cm.span_to_snippet(span);
assert_eq!(snippet, Ok("second line".to_string()));
}
#[test]
fn t9() {
// Test span_to_str for a span ending at the end of filemap
let cm = init_code_map();
let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
let sstr = cm.span_to_string(span);
assert_eq!(sstr, "blork.rs:2:1: 2:12");
}
/// Test failing to merge two spans on different lines
#[test]
fn span_merging_fail() {
let cm = CodeMap::new(FilePathMapping::empty());
let inputtext = "bbbb BB\ncc CCC\n";
let selection1 = " ~~\n \n";
let selection2 = " \n ~~~\n";
cm.new_filemap_and_lines(Path::new("blork.rs"), inputtext);
let span1 = span_from_selection(inputtext, selection1);
let span2 = span_from_selection(inputtext, selection2);
assert!(cm.merge_spans(span1, span2).is_none());
}
/// Returns the span corresponding to the `n`th occurrence of
/// `substring` in `source_text`.
trait CodeMapExtension {
fn span_substr(&self,
file: &Lrc<FileMap>,
source_text: &str,
substring: &str,
n: usize)
-> Span;
}
impl CodeMapExtension for CodeMap {
fn span_substr(&self,
file: &Lrc<FileMap>,
source_text: &str,
substring: &str,
n: usize)
-> Span
{
println!("span_substr(file={:?}/{:?}, substring={:?}, n={})",
file.name, file.start_pos, substring, n);
let mut i = 0;
let mut hi = 0;
loop {
let offset = source_text[hi..].find(substring).unwrap_or_else(|| {
panic!("source_text `{}` does not have {} occurrences of `{}`, only {}",
source_text, n, substring, i);
});
let lo = hi + offset;
hi = lo + substring.len();
if i == n {
let span = Span::new(
BytePos(lo as u32 + file.start_pos.0),
BytePos(hi as u32 + file.start_pos.0),
NO_EXPANSION,
);
assert_eq!(&self.span_to_snippet(span).unwrap()[..],
substring);
return span;
}
i += 1;
}
}
}
}
Reference in New Issue View Git Blame Copy Permalink